Most of electronic products, particularly, TVs or the like, use a remote controller so that a user may control the electronic products while sitting on a sofa or the like without directly pressing various function buttons attached to the main body, such as buttons for volume control, channel switch, power on/off or the like.
However, the remote controller should be used within a predetermine distance since its output power is low, and if there is an obstacle, an infrared remote controller may not be in effect since infrared rays may not arrive at the electronic product by the nature of light.
In addition, although the remote controller should be placed near the electronic product to be used at any time, if the remote controller is placed at a position where the electronic product is not installed or the remote controller is dropped down under a sofa and could not be found, the user may suffer from inconvenience of directly handling the electronic product. However, since most of families do not prepare an extra remote controller, a user should bear the inconvenience of directly handling the electronic product if he or she does not find the remote controller momentarily.
In order to solve the problems described above, a prior art devised to allow a user to use a remote control function in a cellular phone is disclosed in Korean Laid-open Utility Model No. 2000-0001257, in which a remote control transmission unit for transmitting a certain optical signal is provided at the output port of the microcomputer of the cellular phone, and a remote control function selection key is additionally provided in an key input unit.
FIG. 1 is a circuit block diagram showing a cellular phone having a remote control function according to the prior art.
A cellular phone having a remote control function according to the prior art includes a wireless transmission unit 1 for transmitting a voice data as an RF signal, a wireless reception unit 2 for receiving an RF voice signal, a microcomputer 3 connected to the wireless transmission unit 1 and the wireless reception unit 2, for controlling each device in the cellular phone, a key input unit for inputting various key data by a user, a display unit 4 for displaying various kinds of display information under the control of the microcomputer 3, and a remote control transmission unit 6 having a light emitting means for transmitting a corresponding optical signal when the user selects a variety of function keys while pressing a remote control function selection key 5 on the key input unit.
Although the cellular phone having a remote control function according to the prior art includes the remote control function therein, it is inappropriate as a today's cellular phone, which tends to be miniaturized and light weighted, since devices such as the remote control function selection key, the remote control transmission unit and the like are added.
In addition, although digital devices that can be handled using a remote controller, i.e., a remote control device, and improve convenience of use are limited to TVs, audio systems and the like in the past, in which channel switch and volume control are frequently needed, its application is extended recently to various digital devices such as cooling and heating facilities including an air conditioner, an electric fans or the like, DVD players, lighting equipments and the like.
However, although the remote controller should be always kept near the digital device in order to handle the digital device using the remote controller, unlike a remote controller which is always put on a sofa or the like in front of a TV since a place for watching the TV is limited to the front of the TV, a remote controller for another type of digital device is not placed at a specific position, and a user frequently looks for the remote controller to handle the digital device.
In addition, as the types and functions of digital devices handled by a remote controller increase, handling keys and interfaces of each remote controller are diversified and complicated, and thus users may not sufficiently utilize all the functions provided in the remote controller.
In addition, it is general that the remote controller transmits an infrared signal formed in a binary code including a custom code for identifying a manufacturer and a digital device to be controlled and a data code which is a control command, and only a specific digital device may recognize the infrared signal and control a relevant function.
Accordingly, it is general in the prior art that an infrared signal is created and transmitted in a method unique to a manufacturer using a binary signal of different time and length, i.e., by varying length of a high or low pulse for information coding, so as to identify a digital device from a variety of digital devices and create a control command for the digital device based on a simple binary code.
In addition, even in the products manufactured by the same manufacturer, a different custom code is assigned to each digital device in order to prevent malfunctions occurred due to confusions among control commands. Therefore, since a variety of digital devices manufactured by a large number of manufacturers respectively have a custom code different from the others, digital codes used for remote controllers are configured quite diversely.
Accordingly, universe remote controllers are proposed recently, in which all domestic and foreign manufacturers and custom codes of all digital devices sold by the manufacturers are stored in advance, and a custom code matched to a custom code included in an infrared signal actually transmitted from a remote controller is extracted and stored to be used as a custom code of a corresponding digital device.
However, such a universe remote controller of the prior art has a problem in that it is practically impossible to store all the custom codes in advance for all the products newly released in recent days, and it is considerably inconvenient to search for and extract a matched custom code.
Furthermore, the universe remote controllers of the prior art also have limitations of a remote controller itself in that a digital device should be handled by transmitting an infrared signal in front of the digital device, and inconvenience of paying attention to keeping the remote controller still remains.
In addition, although a cellular phone including a remote controller has been proposed in the prior art based on the idea that the cellular phone is placed nearby at all times, there are not so many digital devices that can be operated using the remote controller, and a remote controller interface displayed on the cellular phone is quite simple in many cases so as to allow only simple handlings using a keypad, and thus it is not used very much, and a plenty of space should be secured in the cellular phone in order to install an infrared ray generation unit. Therefore, it is general that recently manufactured cellular phones, i.e., smart phones, are released excluding the infrared ray generation unit.
Accordingly, although an apparatus for combining a separate infrared ray generation apparatus with a smart phone is proposed recently so that a smart phone released excluding the infrared ray generation unit may be used as a remote controller, there is a problem in that it is troublesome to carry the infrared ray generation apparatus at all times and use the infrared generation apparatus in combination with the smart phone.
In addition, recently, the need of controlling on/off of digital devices, such as a plurality of electronic products placed inside of a home, even when a user is outside as well as inside of a room is increased, and to this end, it is tried further more to construct home automation within a home based on a ubiquitous environment. However, there is a problem in that the home automation based on a ubiquitous environment is restrictedly used only for newly constructed luxury houses, not actively used for existing general houses, since too much cost is required to construct the system, and in addition, a work or the like for constructing the system is troublesome.